Browsing by Author "Vanlauwe, Bernard"

Now showing 1 - 7 of 7
  • Does the combined application of organic and mineral nutrient sources influence maize productivity? A meta-analysis
    Chivenge, P. P.; Vanlauwe, Bernard; Six, J. (Springer Netherlands, 2011)
    In Sub-Saharan Africa, soil quality declines as population pressures and low yields push the intensity of agricultural production upward. This meta-analysis offers a valuable insight on which external-input sources will have the most impact on Sub-Saharan African maize yields, nitrogen use efficiency, and soil organic carbon (SOC). Fifty-seven studies comprising 104 experimental sites in twelve countries (Benin, Burkina Faso, Cote d'Ivoire, Ethiopia, Ghana, Kenya, Malawi, Nigeria, Tanzania, Togo, Zambia, and Zimbabwe) were grouped according to the application of Organic Resources (OR), nitrogen fertilizers, and OR and N fertilizers. OR quality was further divided into four classes of decreasing qualities. Maize yields increased with increasing OR quality, both with and without N fertilizer application. Greater yield responses were seen with OR and N fertilizer application, however there is no evidence to suggest this was due to improved N use efficiency, as N use efficiency after combined applications was lower compared to N fertilizer application alone. SOC increase was observed in OR and OR and N fertilizer application, but not in N fertilizer application alone. These results suggest that nutrient storage increases with application of higher quality ORs and low levels of N may be added in conjunction with OR to achieve higher yield responses, but not to increase N use efficiency.
  • A fourth principle is required to define Conservation Agriculture in sub-Saharan Africa: The appropriate use of fertilizer to enhance crop productivity
    Vanlauwe, Bernard; Giller, Ken; Corbeels, Marc; Gerard, B.; Nolte, C. (2014)
    Conservation agriculture (CA) is often promoted as a key to intensifying agricultural production in sub-Saharan Africa. Despite significant efforts to promote CA, however, adoption remains limited in this region. This article contends that CA requires a fourth principle of appropriate fertilizer use to complement the already accepted principles of minimal tillage, maintaining a soil cover, and crop diversification. In regions where CA was widely adopted, fertilizer application was an essential part of agricultural systems, and a key to the success of CA. Appropriate fertilizer application is necessary for CA to be a successful alternative to conventional production in sub-Saharan Africa.
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    Integrated soil fertility management in practice in western Kenya
    Vanlauwe, Bernard; Rotich, E.; Okalebo, R.; Bationo, A.; Mukalama, J.; Ekise, I. (The Tropical Soil Biology Fertility Institute(TSBF)of The International Center for Tropical(CIAT) Agriculture, 2004)
    TSBF-CIAT and its partners are working in western Kenya to develop, evaluate and disseminate integrated soil fertility management practices in which legumes are a prominent component. A substantial part of this work is implemented through PhD projects co-supervised by Cornell University, Wageningen University and TSBF-CIAT. A field trip by scientists from TSBF-CIAT, the Rockefeller Foundation, Kenya Forestry Research Institute (KEFRI), Moi University, Cornell University and Wageningen University to some of the research sites on 10 11 November 2003 examined the progress in these activities. This newsletter/report summarizes some results of the various projects.
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    Prospects for integrated soil fertility management using organic and inorganic inputs: evidence from smallholder African agricultural systems
    Place, Frank; Barrett, Christopher B.; Freeman, H. Ade; Ramisch, Joshua J.; Vanlauwe, Bernard (Elsevier, 2003)
    This paper reviews current organic nutrient management practices and their integration with mineral fertilizers in Sub-Saharan Africa with a view to understanding the potential impacts on a range of input markets. A number of different organic nutrient management practices have been found to be technically and financially beneficial, but they differ considerably as to their effectiveness and resource requirements. A review of African smallholder experiences with integrated soil fertility management practices finds growing use, both indigenously and through participation in agricultural projects. Patterns of use vary considerably across heterogeneous agroecological conditions, communities and households, but are stimulated by profitable commercially oriented agricultural opportunities. The potential for integrated soil fertility management to expand markets for organic inputs, labor, credit, and fertilizer is explored. We found that there are few direct analyses of these links and the current indirect evidence is inconclusive.
  • The Role of Fertilizers in Integrated Plant Nutrient Management
    Alley, Marcus M.; Vanlauwe, Bernard (Paris, France: International Fertilization Industry Association, 2009)
    This book explores the Integrated Plant Nutrient Management (IPNM) approach and its advantages and disadvantages. The goal of IPNM is to optimize nutrient growth by analyzing nutrient use from agronomic, economic, and environmental perspectives. This optimization is achieved by nourishing a crop as efficiently as possible while avoiding adverse environmental impacts. IPNM is a joint effort and requires the cooperation of many different stakeholders to make IPNM successful. This book offers IPNM explanations, strategies and suggestions for stakeholders, and three case studies from Sub-Saharan Africa, China, and North America.
  • Socio-ecological niches for minimum tillage and crop residue retention in continuous maize cropping systems in smallholder farms of central Kenya
    Guto, S. N.; Pypers, P.; Vanlauwe, Bernard; de Ridder, N.; Giller, Ken (Madison, WI: American Society of Agronomy, 2011)
    The prevalence of soil degradation and production constraints for smallholder farmers in Central Kenya offers an opportunity for the application of conservation agriculture practices. However, much variability exists between smallholders, rendering the benefits of CA quite site specific. The purpose of this study was to determine the effects of minimum tillage and mulches on maize yields of twenty-one farms with varying soil fertility, size, and, cropping seasons. Two tillage and two crop residue trials were compared across three soil fertility classes from 2007 to 2009. It was determined that minimum tillage practices are inappropriate for good and poor soil fertility and most beneficial for farms of medium soil fertility. In order to raise agricultural productivity in Sub-Saharan Africa, additional studies that account for heterogeneity among smallholders is critical.
  • Tillage and vegetative barrier effects on soil conservation and short-term economic benefits in the Central Kenya highlands
    Guto, S. N.; Pypers, P.; Vanlauwe, Bernard; de Ridder, N.; Giller, Ken (Elsevier, 2011)
    Integrating vegetative soil erosion barriers with minimum tillage practices can be an economically viable method in reducing soil loss in intensively managed sloping land in the East African Highlands. This study sought to compare minimum and regular tillage practices with and without vegetative barriers (leucaena and Napier) under local farming conditions in Kenya. Minimum tillage yields of soybean and maize were superior to conventional, except in instances of root competition within the Napier no-till trial. Minimum tillage trials without barriers experienced significant soil loss during periods of heavy rainfall and had the lowest marginal rate of returns. Napier barriers with conventional tillage conserved the most soil and represented an economically viable option; however, leucaena barrier use couple with conventional tillage was found to be a less risky practice with even greater economic returns. Longer term studies in multiple locations are necessary to determine impacts across a highly varied cohort of smallholder farmers in the African Highlands.